Controlled feed mechanism for yarn



Jan. 15, 1963 H. G. PosT ETAL 3,073,139

coNTRoLLED FEED MECHANISM FOR YARN Filed May 2s, 1960 F/G. l.

/N VEN TORS A TTORNE Y United States Patent() L 3,073,139 CONTROLLEDFEED MECHANISM FOR YARN Herbert G. Post, 5792 Crescent Ave., Buena Park,Calif., and'William L. Carroll, 328 N. Newlin, Whittier, Calif. FiledMay 23, 1960, Ser. No. 30,918 6 Claims. (Cl. 66-132) This inventionrelates to an improved controlled feed mechanism for yarn and has -forone of its principal objects the provision of a device of the classdescribed, which will automatically maintain a predetermined tension ona strand of yarn which is being fed off a bobbin to a knitting machineor the like.

- One of the important objects of this invention is to provide a-methodand apparatus for feeding strands of yarn or thread, which are more orless elastic, at a uniform tension to the needles of a knitting machineor similar apparatus.- Another object of the invention is to provide anew and improved yarn feeding mechanism which will automatically varythe rate of feed of the yarn in accordance with the demand therefor bythe knitting machine itself.

Another and still further important object of the invention relates tothe provision of a yarn tensioning device which will automatically feedthe strands under uniform tensionirrespective o f the speed at which theyarn being'f'edis'taken up. l f. Yet another object ofthe-inventionresideslin; theprlo'- visionof-a simpleyyet effective, means vvforautomatically controlling and equalizing the tension on a plurality ofstrands of yarn or similar materials which arebeing fed into aprocessing machine, whereby undesirable and unsightly imperfections inthe final product are avoided. 1 Other and further important objects ofthe invention will be apparent from the disclosures in the accompanyingdrawings and following specification. The invention, in a preferredform, is illustrated in the drawings and hereinafter more fullydescribed,

In the drawings:

FIGURE 1 is an illustration, somewhat diagrammatic,

iof the essential parts of the-strand feed controlling .mechanism ofthis invention.

FIGURE'Z is'an enlarged detail view, taken on the 'plane of the line 2-2of FIGURE 1, looking in the direction indicated by the arrows.

FIGURE. 3 is an enlarged detail sectional view on the -line 3-3 ofFIGURE l, looking in the direction indi cated, and with certain partsbroken away.

-' t FIGURE 4 is a wiring diagram illustrating the action of two ofthe`automatic yarn tension control devices of The yarn 16 ispreliminarily passed through an eyelet for guide 18 in asupport 20 andthen to a conventional .tensioning device 22. These elements are allmounted on the frame 10 in any desired or convenient manner.

ing apparatus of this invention. A 'stand 12 is provided `to support abobbinv14 of yarn 1,6. if

'A lmotor 24 is mounted beneath the frame 10, and the shaft of thismotorv drives a yarn feed wheel 26. This feed wheel contacts ajuxtaposed wheel 28 (FIGURE 2) supported by a suitable bracket or thelike'30 from the correspondingly rounded to fit in the groove of thewheel 52S' and thereby 'provide a'non-slippingrgrip upon the.;

frame 10, and any .suitable means is providedfor main-i strand 16 .whichis being fed between the wheels whenever the motor 24 is turning.

From an inspection of FIGURE 4, it will be evident that a plurality ofmotors 24 is employed in one complete knitting mechanism, and these areusually arranged in a circle about the knitting machine, whereby asuitable satisfactory feeding of the numerous strands of yarn iseffected, and without any possibility of slippage at the feed wheels.

A bracket 32, fastened to the underside of the frame 10, supports aneyelet or guide 34 through which the strand 16 is possed, and anotherguide 36 is mounted on the end of an adjustable arm 38 pivoted at 40 toa supoprt 42 which is an extension of the bracket 32 (FIGURE 3).

A permanent magnet 44 is on the end of the arm 38, and this is mountedin juxtaposition with a tiltable mercury switch 46 also on the bracket32. The tiltable portion of the mercury switch is indicatedschematically by the switch blade 45.

The switch is normally open, and a pair of wires 50 leads from theswitch to a resistor or other motor speed control element 52, as bestshown in FIGURE 4.

From the guidel or eyelet 36, the strand 16 is then led either directlyto the needle bedl54 vor through an addi- 'tionalguide, if s uchbecomesnecessary; j, i. The mercury switch 46 is either in-or ,attachedtoa soft iron housing, not' shown-whereby counter-clockwise movement ofthe-magnet 4 4 from'thefpos'ition illustrated in FIG. 4 tojapositinimmediately adjacent theA switch 46 will tilt the switch, causingthe same to close, thereby momentarilyspeeding up the motor 24, which isof the direct current type for this purpose. v

in operation, each and every one of the plurality of motors 24, whichform part ofthe complete'mechanism, is preliminarily-set for apredetermined speed by means of a mastercontrt, as indicated more'orless diagrammatically aty60 in FIGURE 4 and which is part of the circuitwhich' controls all the motors'and includes the respective mercuryswitches.

Yarns 16 from the numerous bobbins 14 are then brought through 18 tolthe'conventional tensioners 22 "and then to the respective yarnfeed'wheels 26-28 and finally through the guides 34 and 36 tothe needlebed 54. All of the motors 24 are then synchronized to operate at thesame speed of any desired or necessary revolutions per minute, therebycausing each and every oneof the fof strands 16 is not being fed at asufficient rate of speed to supply the demands of its respective needle,the slightest=pull resulting from this inc reased tension will tilt thearm 38 about its anti-friction bearing pivot 40, causin'g the magnet 44to shift its position sufficiently to close the mercuryy switch 46. Thisactuatesthe resistor 52`to vimmediatelyfeed an increased supply ofcurrent to that particular motor 24, speeding up the-same to a suicientdegree to release the excess tension on the related strand 16 whereuponthe magnet 4 4 will move back into its Yoriginal position, opening theswitch 46 and accordingly moving the resistor 52 back to its originalposition, again reducing the motor speed to its original pre-set'revolutions per minute and again presenting a normal feed speed.

The switch 46-need not be of the mercury type, as other switches withproper environmental operating means will perform satisfactorily. "Onetype of mercury switch has a soft iron core built into its glass housingand this operates very satisfactorily. The element 60 comprises arheostat, and this is employed to preliminarily adjust the feedl motors24 to'aspeed just below the amens take-up speed at the needle bed 54,and this is done in combination'with the adjustable resistor 52 and withthewnlagnetically operated switch 46 in open position.

rlfhe operator -then checks to ascertain that the speed of the feedmotor 'or motors 24 is above needle take-up speed when the switch 46 isclosed. Closing of this switch shorts out the`r'esistor 52 andaccordingly'raises the speedr of that particular inter-connected feedmotor; "lhe feed fnoto'r fields may be separately excited for betterregulation.

When Ithe main motor or take-up is energized, the feed motors alsostart', and at this point, .a slight over-feed of yarn or strand isinitiated, rboth on the start or stop of the main motor. Then when, forany`reason, the length of the yarn 16 is decreased'between Ithe feedwheels and the needle bed, the switch 46 is immediately actuated,causing a slight over-feed of that yparticular strand of yarn byincreasing the speed of that individual motor 24. This slightover-feed-continues until the tension on the yarn is lessened to4 adegree allowing the outer end 36 of the 'pivoted arm $8 tonrisefopeningthe switch 46 and permitting the motor 24 rto accordingly run at aslightly slower speed because of passage of current through resistor 52This action of alternate over-feeding and underfeeding is'c'ontinued solong .as the main motor or take-up continues to operate.l i'

It will be evident that herein is provided a simple, yet efficient?apparatus and method of feeding and controlling yarn or similarmateialin the textile industry and which automatically overcome allvariablesoriginating at the .source of supply, sufc'h as a bobbin, 'andwhich -will further vthen automatically deliver said Ayarnor otherinaterial tQ"a" tak'e-up'or .similar Iapparatus at a controlled rate notension and regardless of the rate of delivery required by the take-up'or similar equipment. i

This will improve the quality of the final product, decrease undesirablestoppages, render maintenance more easy, facilitate .rapid `andvaccurate set-ups and changeovers and will generally increase over-allefficiency.

Qne of the real problems now existing in this industry has not beensolved because ofthe lack of a suitable apparatus and method which .thisinvention provides. Presentday`m'ethods'allow thetake-up or otherapparatus to pull the yarn or other material directly from the sourceand usually through various tensioning and compensating devices in aneifort to vutilize` variables at the source. Some of these variablesarecaused under-winding, improper packaging', knotsl and variances in thedistance from the sottrae to the Vtake-'up `Present feeding vmechanismsde- Vcrease the .variables but" do not eliminate them entirely `becausethe compensators employed willV not and cannot synchronize a multiple of"strands between the plurality of sources and single take-up mechanism,particularly over any extended periodof'time, These compensating meth-'ods' attempt `to regulate Vthe amount of material entering the take-upbyphysicallyrnoving the position of the strand or by overffeeding orunde,1i-feeding.Y Such methods which allow the take-up to move thecompensator' before it can assure a proper feeding will induce avariable in the strand, whiilhrwillinevitably appear in the finishedprodnot way ofy imperfections, and themainV reason for this deiicienc-yis slow reaction time in the various compen- ,Stoors now enrloyedl Theapparatus of this invention will minutely and alternatvely over-feed andunder-feed the yarn or other material to the take-up or other apparatus,as required, so there is never any appreciable change in the effectivelength of the strand beingl fed. The method and apparatus of thisinvention assures that any changes in strand length are always at l anabsolute vpredetermined minimum, and

these will never change, regardless of any variables at the source -orat the take-up.V The` monitoring device of this invention which, whenonce preliminarily adjusted and calibrated, jwill'subsequently reactimmediately and properly determine overt-feedandnndeI-feed.

The feed Wheels 26 and 28 are controlled and tuned very minutely,slightly under the natural demand of the take-up or other apparatus,whereby only a very small increase of speed by way of a fine toleranceis required for only a very short space of time. This is accomplished bythe very low friction pivot 40 for .the magnet arm 38 which activatesthe switch 46 through magnetic lines of flux and the complete absence ofany mechanical connection.

Accordingly this invention presents an automatic control for therelatively high speed at which most circular knitting machines operateand will correspondingly increase the rate of feed of the yarn Wheneverthe tension on any particular strand increases above optimumoperatingrelationship. Also, as soon as the tension is lessened,- theparticular motorwill be automatically returned to normal operatingspeed, which is equal yto the demand of the take-up means whilemaintaining the yarn under uniform tension, although the demandmayconsiderably vary the rate of travel of the yarn itself. vThis'particular device can'be readily adapted for use with various typesorf knitting machines, even though the same varyviny speedrequirementsvover a relatively wide range. The unit is obviously of verylight construction and extremely sensitive to even the slightestvariations in tension so that a uniform supply of ya'rn is fed to theknitting machine itself at all times and a much better final productwill inevitably result. We are aware that many changes may be made andnumerous details of construction varied throughout a wide range withoutdeparting from the. principles of this invention; and we', therefore, donot'p'ropcse limiting the patent granted hereon otherwise than asnecessitated bythe prior art.

We claim as our invention:

l. In a devicefo'r controlling the feed tension of a strand of yarn atthe needle bed of a knitting machine, the combination of: a pair of yarnfeding Wheels; a motor for driving said yarn feeding wheels; guide meansfor a strand of y-arn interposed between said feeding wheels and saidneedle bed, said guide means including a pivoted arm supporting one ofsaid'guide means and mounted for pivotal movement in response tochangesin yarn tension at said needlebed;l anv electrical controlcircuit for said motor actu'atable by said pivoted arm, said controlcircuit including a normally o-pen magentically energized switchoperable by said lpivoted arm; vand a resistor adapted to be shorted bysaid switch to momentarily increasev the speed of said motor when saidpivoted arm is deflected to energize saidimagnetio switch. i

2. In a device for controlling the feed tension of a strand of yarn atthe needle bedof a knitting machine, the combination of: yarn feedingmeans; a motor for driving said yarn feeding means; guide' means for astrand of yarn interposed between said feeding means.. and said needlebed, said guide means including a pivoted arm supporting one of saidguide means and mounted for pivotal movement in response to charges inyarn tension at said needle bed; an electrical control circuit forsaidmotor actuatable by said pivoted arm, said lcontrol circuit including anormally open magneticallyenergized switch operable hy said pivotedarmi; and a resistorv adapted to ybe shorted by said switch tomomentarily increase the speed of said motor when said pivoted arm isdeflected to energize said magnetic switch.

3. In a device for controlling the feed tension of a strand of y-arn atthe needle lbed of a knitting machine, the combination of: yarn feedingmeans; a motorconnected to'said yarn feeding means `for drivingfthesame; guide means interposedbetween said yarn feeding-means vandsaidneedle bed, said guide means includingy an Yelongated pivoted armhaving a ,portion engaging said yarn motor and said pivoted arm, saidelectrical control circuit including a rheostat for initially settingthe speed of rotation of, said motor, a normally open magnetic switchoperable by said pivoted arm and a resistor connected in said circnitand adapted to be shorted out when said switch is closed by the actionof said pivoted arm.

4. in a device for controlling the feed tension of a strand of yarn atthe needle bed of a knitting machine, the combination of: a pair of yarnfeeding wheels; a motor connected to said yarn feeding wheels fordriving the same; guide means interposed between said yarn feedingwheels and said knitting machine, said guide means including anelongated pivoted arm having a portion engaging said yarn strand, saidportion being mounted for pivotal movement in response to changes inyarn tension at said needle bed; and an electric control circuitinterposed between said motor and said pivoted arm, said electricalcontrol circuit including a rheostat for initially setting the speed ofrotation of said motor, a normally open magnetic switch operable by saidpivoted arm and a resistor connected in said circuit and adapted to beshorted out when said switch is closed by the action ot Said pivotedarm.

5. In a device for controlling the tension of a strand of yarn at thenecdie bed of Ia knitting machine, the combination of: positive feedingmeans engageable with said strand; a motor connected to said positivefeeding means to drive the same; movable guide means engageable withsaid strand and mounted for movement in response to changes in yarntension at said needle bed; and an electrical control circuit interposedbetween said motor and actuable by said movable guide means, saidelectrical control circuit including a normally open switch actuatahieby said movable guide means and motor speed control means in saidcircuit adapted to be operated by said switch to alter the speed of saidmotor when said switch is closed by said movable guide means.

6. In a device for controlling the Vtension of a strand of yarn at theneedle bed of a knitting machine, the com bination of: positive feedingmeans engageable with said strand; `a motor connected to said positivefeeding means to drive the same; movable guide means engageable withsaid strand and mounted for movement in response to changes in yarntension at said needle bed; and an elec- References Cited in the le ofthis patent UNITED STATES PATENTS 2,248,88l Lawson July 8, 19412,810,936 Altenburger Oct. 29, 1957 2,949,757 Page Aug. 23, i960

1. IN A DEVICE FOR CONTROLLING THE FEED TENSION OF A STRAND OF YARN AT THE NEEDLE BED OF A KNITTING MACHINE, THE COMBINATION OF: A PAIR OF YARN FEDING WHEELS; A MOTOR FOR DRIVING SAID YARN FEEDING WHEELS; GUIDE MEANS FOR A STRAND OF YARN INTERPOSED BETWEEN SAID FEEDING WHEELS AND SAID NEEDLE BED, SAID GUIDE MEANS INCLUDING A PIVOTED ARM SUPPORTING ONE OF SAID GUIDE MEANS AND MOUNTED FOR PIVOTAL MOVEMENT IN RESPONSE TO CHANGES IN YARN TENSION AT SAID NEEDLE BED; AN ELECTRICAL CONTROL CIRCUIT FOR SAID MOTOR ACTUATABLE BY SAID PIVOTED ARM, SAID CONTROL CIRCUIT INCLUDING A NORMALLY OPEN MAGNETICALLY ENERGIZED SWITCH OPERABLE BY SAID PIVOTED ARM; AND A RESISTOR ADAPTED TO BE SHORTED BY SAID SWITCH TO MOMENTARILY INCREASE THE SPEED OF SAID MOTOR WHEN SAID PIVOTED ARM IS DEFLECTED TO ENERGIZE SAID MAGNETIC SWITCH. 